An organic light-emitting display apparatus includes a first sub-pixel, a second sub-pixel, and a third sub-pixel configured to emit different colors of light. The organic light-emitting display apparatus includes: a substrate; first through third pixel electrodes; a first organic emission layer configured to emit light having a first wavelength; a second organic emission layer configured to emit light having a second wavelength; a third organic emission layer configured to emit light having a third wavelength; an opposite electrode; a capping layer over the opposite electrode and having a refractive index with respect to the first wavelength that is higher than a refractive index with respect to the second wavelength by at least 7%; and a thin-film encapsulation layer over the capping layer.